Steam distribution system

ABSTRACT

A system for distributing steam to a travelling web includes an elongated chamber having numerous steam distribution outlets arranged therealong and a steam inlet manifold extending lengthwise along the interior of the chamber. A plurality of ports formed along the manifold serve to admit steam from the manifold to the chamber. A system of manually adjustable valves individually controls the amount of fluid passing through each port from the manifold into the chamber to thereby enable an operator to selectively establish various profiles of steam distribution. In a preferred embodiment the system is located above the web. The steam distribution outlets are directed downwardly and each is surrounded on the interior of the chamber by an upstanding ferrule which prevents condensation from passing from the chamber onto the web.

United States Patent [72] Inventor Clifford D. Shelor Covington, Va.[2|] Appl. No. 877,615 [22] Filed Nov. 18, 1969 [45] Patented Apr. 13,1971 [73] Assignee Westvaco Corporation New York, N.Y.

[54] STEAM DISTRIBUTION SYSTEM 13 Claims, 4 Drawing Figs.

[52] U.S. Cl 239/553.3, 239/557, 239/562 [51] Int. Cl B05b 1/14 [50]Field of Search 239/557, 562, 5 5 3. 3

[56] References Cited UNITED STATES PATENTS 3,508,71 1 4/1970 Switall239/562 Primary Examiner-Carroll B. Dority, Jr. Attorneys-Robert S.Grimshaw and James L. Neal ABSTRACT: A system for distributing steam toa travelling web includes an elongated chamber having numerous steamdistribution outlets arranged therealong and a steam inlet manifoldextending lengthwise along the interior of the.

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53 INVEN'IORQ CLIFFORD D. SHELOR Ill/f STEAM DISTRIBUTION SYSTEM SUMMARYOF THE INVENTION Apparatus for controllably distributing steam upon asurface includes a steam distribution chamber having a multiplicity ofspaced steam distribution outlets. The inlet for the steam distributionchamber includes a plurality of ports arranged for individual fluidcommunication with the chamber. Associated with each of the ports is avalve means by which the fluid flow from the ports to the chamber iscontrolled. By the valve means, a high degree of regulation is exertedupon the pattern of fluid flow into the chamber. The result is variablecontrol of the total volume of steam output from the chamber and also ofthe volumetric pattern of steam output across the area in which thesteam distribution outlets appear. The volumetric pattern of steamoutput across the area in which the steam distribution outlets appear isherein designated the steam distribution profile.

In the preferred embodiment, an elongated inlet manifold defines theinlet ports and is enclosed by an elongated housing which forms a steamdistribution chamber surrounding the manifold. The ports are arrangedalong the length of the manifold so as to admit steam into the chamberalong its entire length. A valve is provided at each port forindividually controlling the flow therethrough. Formed along the lengthof the chamber area multiplicity of steam distribution outlets throughwhich the steam passes to the material upon which it is being applied.The steam distribution profile in this embodiment is the volumetricpattern of steam output along the length of the chamber. It will readilybe appreciated that the profile at the steam distribution outlets is afunction of the amount of steam passing from the manifold, through eachof the various ports, into the chamber. Since each valve is individuallycontrollable, the apparatus is capable of selectively providing a widevariety of steam distribution profiles. Valve adjustment may be designedto produce even flow through all the steam distribution outlets (i.e., aflat steam distribution profile). On the other hand, if an irregularprofile is desired, the valves may be adjusted to provide greater flowthrough steam distribution outlets in certain selected areas of thechamber.

Each of the steam distribution outlets of the preferred embodiment issurrounded by an inwardly extending ferrule. These ferrules serve toprevent the passage of condensation through the outlets when the outletsare downwardly directed.

A primary object of this invention is to provide a steam distributionsystem which is adjustable to selectively vary the volumetric pattern ofsteam output across a surface having a multiplicity of steam outlets.

Another object of this invention is to provide a steam distributionsystem having a manifold which delivers steam to a steam distributionchamber through a plurality of valved A further object of this inventionis tor provide a steam distribution system having an improved condensatedrain system.

BRIEF DESCRIPTION OF THE DRAWINGS DETAILED DESCRIPTION OF A PREFERREDEMBODIMENT The steam application system of this invention isparticularly useful for steam drying a continuously moving paper webduring formation thereof. The application of dry steam to such a webraises its temperature and thereby raises the temperature of waterretained therein. The viscosity of water decreases as its temperatureincreases and the decrease in viscosity, of course, serves to facilitatewater removal during the paper formation. Numerous locations along thepapermaking machine are appropriate for steam application. Two areillustrated in connection with the apparatus of FIG. 1.

The Fourdrinier type papermaking machine 10 illustrated in FIG. Icomprises a headbox 11 for delivering stock consisting of a fiber slurryto a Fourdrinier wire 12. The Fourdrinier wire is trained over a breastroll 14, a couch roll 16 and a turning roll I5. Beneath the upper pathof the Fourdrinier wire are a plurality of table rolls l8 and aplurality of vacuum boxes 20 for draining fluid from the slurry, to formweb 23 upon the wire I2. A plurality of idler and guide rolls 22 areprovided for the lower path of wire 12. Couch roll 16 includes suctiongland 17 for removing additional fluid from the web as the web passesover the couch roll and just before it leaves the wire.

From the Fourdrinier wire, the web passes through a press section andthen through a drier section. The press section illustrated in FIG. 1comprises first and secondlike press stations 25 and 25, respectively.Each station includes a loop of felt 24 drawn over a series of idler andguide rolls 26 and a stretch roll 28. Along the upper path of felt loop24 is mounted a pair of wringer rolls 30 and 32. Included in eachwringer roll 32 is a suction box 34. The wringer rolls press the webagainst the felt and, in cooperation with suction gland 34, removeadditional fluid from the web. From the press stations 25 and 25' theweb passes through a smoothing press 36 and thence to driers 38.

Steam applicators installed at a given location may include a bank ofapplicators or a single applicator. Referring again to FIG. I, a bank 40of individual steam distributors 42 are installed over the Fourdrinierwire in advance of couch roll I6; a second bank 44 of individual steamdistributors 42 are installed over the first breast station 25, inadvance of wringer rolls 30 and 32. During the papermaking operation,the banks of steam distributors operate to increase the temperature ofthe web at the designated locations. In the manner discussed above, thelowered viscosity of the water in the web enhances water removaloperations and results in an increase in the amount of water drawn fromthe web as it passes over vacuum gland 17 in couch roll 16 and as itpasses between wringer rolls 30 and 32, over suction gland 34.

A steam applicator 42 will now be described in detail in connection withFIGS. 2 through 4. A tubular housing 50 forms an elongated steamdistribution chamber 68 having a multiplicity of steam distributionoutlets 52, each of which consists of an opening in the housing having aferrule 54 set therein. The ferrule includes a central bore 56, whichdetermines the effective size of steam distribution outlet, and anupstanding portion 58. Portion 58 forms a fluid barrier which serves toprevent the passage from the steam distribution chamber of anycondensation which may form therein during operation of the steamdistribution apparatus, when steam distribution outlets 52 aredownwardly directed, as will be more fully explained below.

Tubular housing 50 is supported by end sections 60 and 62. Supportedwithin housing 50 by end sections 60 and 62 is a cylindrical manifold 64having a diameter which is less than the width of tubular housing 50.Steam distribution chamber 68 surrounds manifold 64. Each end ofmanifold 64 is sealed by an O-ring 66 to prevent undersired fluidcommunication between chamber 68 and the inside of manifold 64.

A steam inlet passage 70 is provided in end section 60 for deliveringsteam to the manifold. A plurality of ports 72 are provided along thesurface of manifold 64 and directed way from steam distribution outlets52. There is provided in association with each of these ports, a needlevalve assembly 74 for controlling the passage of steam through eachport. In the vicinity of each of these needle valves is a saddle 76which assists in maintaining manifold 64 and housing 50 in properrelationship to each other.

Each of the saddles 76 fon'ns a threaded opening 78 for mounting aneedle valve 74. The needle valves 74 each comprise a threaded screw 82,a lock washer and seal 84, a threaded valve steam 86 having seat 88 andhead 90 and a lock nut 92. The screw 82 is tightened into the upperportion of threaded opening 78 of saddle 76. A fluid seal is formed bylock washer and seal 84. Steam passages 80 extend from a lower portionof opening 78 through the saddle so as to direct steam from manifold 64outwardly against the lateral sides of housing 50. A threaded bore 83formed in each screw 82 receives the threaded shank of the valve stem 86so that the seat 88 of the valve stem is positioned for variablycontrolling fluid passage through the port 72. The head 90 of the valvestem is exposed exteriorly of the housing 50 so that the valve stem maybe manually turned to raise and lower the seat 88 relative to the port.Lock nut 92 is provided for securely retaining the valve steam 86 in itsselected position.

End 62 of the steam distribution apparatus forms a tap 94 for a steampressure gauge, not shown, and a tap 96 adapted to receive a drain valvemeans, not shown, for drawing off condensate from the interior ofmanifold 64. Also formed in end section 62 is tap 98 also adapted toreceive a drain valve, not shown, for drawing off any condensate whichmay collect within chamber 68. It should be noted that, in applicationswhere a continuous flow of steam through the manifold is desired, theconduit forming the manifold 62 may continue through end section 62,thus eliminating the need for taps 94 and 96 and their associatedequipment.

The steam application 42 is mounted above Fourdrinier machine l in anyconvenient manner. End sections 60 and 62 include threaded mountingbores 100 and 102 to assist in the attachment of applicator 42 to asuitable supporting structure, not shown.

In operation, steam is admitted into the manifold 64 through the steaminlet passage 70 at a sufficiently elevated temperature and pressure toyield superheated steam. From manifold 64 the steam passes through theports 72 into the lower portions of threaded openings 78 in saddles 76and thence out through steam passages 80 into chamber 68. The amount ofsteam passing through any given valve 74 is dependent upon the selectedadjustment of that individual valve. As the steam passes from offthrough manifold into the chamber it experiences a pressure drop. Thethrottling process which occurs increases the superheated quality of thesteam and thereby provides, at the outlets 52, a more efficient steamfor heating the web of paper. The steam distributors are placed as nearas practical to the web. A spacing of about I inch provides enoughclearance to avoid interference with the web by the steam distributingapparatus while allowing the steam to traverse the space with a minimumof heat loss. Any steam which condenses in manifold 64 or chamber 68will be drawn off through drains mounted at taps 66 and 68,respectively. The raised water barriers 58 established by the ferrules54 prevent the passage of condensation through the steam distributionoutlets 52.

in certain locations steam distribution apparatus of this invention isinstalled for applying steam to a sloping surface. Such a situation isillustrated in FIG. 1 where bank 44 of steam distributors 42 areinstalled over press station 25. In this application the space 104within the lower corner chamber 68 serves as a passage to conductcondensate to the drain associated with tap 98. The space 104 issufficiently large to avoid spillage of the condensate over the fluidbarrier established by the ferrules 54.

It can be seen that installation of the steam distribution apparatus ofthis invention along papermaking machine will serve to heat the web ofpaper being formed upon the machine and facilitate removal of watertherefrom in the manner described above. Specifically, an application ofsteam just prior to couch roll 17 and above press station 25 in advanceof wringer rolls 30 and 32 heats the web so as to reduce the viscosityof the fluid retained therein and thereby permit an increased amount offluid to be removed as the web passes over the couch roll hand betweenthe wringer rolls, respectively.

The spacing of ports 72 and steam distribution outlets 52 can bedetermined according to the pattern which best suits a givenapplication. Generally, best results are obtained when the diameters ofthe outlets range between one-eighth inch and three-sixteenths inches,the distance between the jets within a row and between the rows of jetsfalls within the range from one-half inch to three-fourths inch, and thesum of the open area defined by the outlets equals substantially 4percent of the area of the plate required to support the outlets. In thepreferred embodiment, bores 56 of the steam distribution outlets 52 areone-fourth inch in diameter and arranged in rows. The distance betweenthe rows and also the distance between any two outlets within a rowequals five-eights of an inch and the rows are staggered so that theoutlets from the equilateral triangular pattern apparent in FIG. 3. Withthis outlet configuration, the sum of the open areas defined by theoutlets is substantially 4 percent of the area of the plate required tosupport them. Further, in the preferred embodiments, it has been foundthat substantial steam distribution profile control can be obtained whenvalved ports occur at approximately 3% intervals along the manifold 64.

It is to be understood that the foregoing description of a preferredembodiment and that the invention is not limited to the specificapparatus shown and described. Therefore changes may be made in thedescribed preferred embodiment without departing from the scope of theinvention.

lclaim:

1. Apparatus for distributing steam comprising:

a. means forming a chamber having a multiplicity of steam distributionoutlets spaced along a portion of its surface;

b. means forming a plurality of steam supply ports in fluidcommunication with diverse portions of said chamber; and

c. means for variably regulating the passage of steam through at least anumber of said ports individually to effect variation in thedistribution of steam throughout said chamber as such steam passesthereinto and thereby produce variation in the steam distributionprofile established at said steam distribution outlets.

2. Steam distributing apparatus according to claim 1 wherein said meansfor variably regulating the passage of steam through a number of saidports comprises a plurality of valves, each valve being mounted forregulating the passage of steam through one of said number of ports.

3. Steam distributing apparatus according to claim 2 wherein the passageof steam through all of said steam supply ports is variably regulated bysaid plurality of valves.

4. Steam distributing apparatus according to claim 3 wherein said steamdistribution outlets are substantially downwardly directed, furthercomprising means forming a raised water barrier surrounding each of saidsteam distribution outlets internally of chamber for resisting passageof condensation from the interior of said chamber through said outlets.

5. Steam distributing apparatus according to claim 1 wherein said steamdistribution outlets are substantially downwardly directed, furthercomprising means forming a raised water barrier surrounding each of saidsteam distribution outlets internally of said chamber for resistingpassage of condensation from the interior of said chamber through saidoutlets.

6. Steam distributing apparatus according to claim 1 wherein saidchamber is of polygonal cross section and said steam distributionoutlets are grouped in a plane face thereof nearer to the junction ofsaid plane face and one intersecting face than to the junction of saidplane face and another intersecting face whereby a condensate conduit isformed at said junction of said plane face and said other intersectingface when said plane face is angularly disposed to the horizontal sothat said junction of said plane face and said other face forms thelower extremity of said apparatus.

7. Steam distributing apparatus according to claim 6 further comprisingmeans forming a raised water barrier surrounding at least a portion ofsaid steam distribution outlets internally of said second chamber forresisting the passage of condensate from the interior of said chamberthrough said outlets.

8. Steam distributing apparatus according to claim 1 wherein said meansforming a plurality of steam supply ports comprises a steam inletmanifold disposed internally of said chamber and connected to a sourceof supply for conveying steam to diverse portions of said chamberthrough said ports.

9. Apparatus for distributing steam comprising:

a. an elongated steam inlet manifold forming a plurality of ports alongthe length thereof;

b. means forming an elongated enclosed chamber surrounding the portionof said manifold along which said ports are distributed;

c. means forming a multiplicity of steam distribution outlets along thelength of said chamber; and

d. a plurality of valves, each valve being mounted for variablyregulating the passage of steam from said manifold through an individualport into said chamber, to thereby vary the distribution of steamthroughout said chamber and permit the establishment of a variety ofsteam distribution profiles at said steam distribution outlets.

10. Apparatus according to claim 9 further comprising means outside ofsaid enclosed chamber for adjusting each of said plurality of valvesindividually.

11. Apparatus according to claim 9 wherein said steam distributionoutlets are substantially downwardly directed, further comprising meansforming a raised water barrier surrounding each of said steamdistribution'outlets internally of said chamber for resisting thepassage of condensation through said outlets from the interior of saidchamber to the exterior thereof.

12. Apparatus according to claim 9 wherein paid steam distributionoutlets are arranged along one side of said enclosed chamber and saidports are arranged linearly along said manifold to face in a directionaway from said steam distribution outlets.

13. Apparatus for distributing steam upon a travelling web comprising:

a. means forming an elongated chamber adapted to be mounted above andextend substantially across said web;

b. means forming a multiplicity of steam distribution outlets along thelength of a substantially downwardly directed portion of said chamber;

c. an elongated steam inlet manifold enclosed within said elongatedchamber and extending substantially lengthwise thereof, said manifoldforming a plurality of substantially upwardly directed ports fordistributing steam through said chamber;

d. a plurality of valves, each one of which regulates the amount ofsteam passing through one of said ports;

e. means outside of said chamber for variably adjusting each of saidplurality of valves individually to thereby vary the distribution ofsteam throughout said chamber and permit the establishment of a varietyof steam distribution profiles at said steam distribution outlets; and

f. means forming a raised water barrier surrounding each of said steamdistribution outlets internally of said chamber for resisting thepassage of condensate through said ou tlets from the interior of saidchamber to the exterior thereof.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,574 IDated M y 5, 1971 Clifford D. Shelor Inventor(s) It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 3, line 42, following "As the steam passes from" delete "offthrough" and insert thetherefor. Columl 4, line 1, following "couchroll", delete "band" and insert -and therefor. Column 6 line 19 (claim13, line 12) delete "through" and insert -throughout therefor.

Signed and sealed this 14th day of September 1 971 (SEAL) Attest:

figgfi ggfi mm. ROBERT GOT'ISCHALK Acting Commissioner of Pa

1. Apparatus for distributing steam comprising: a. means forming achamber having a multiplicity of steam distribution outlets spaced alonga portion of its surface; b. means forming a plurality of steam supplyports in fluid communication with diverse portions of said chamber; andc. means for variably regulating the passage of steam through at least anumber of said ports individually to effect variation in thedistribution of steam throughout said chamber as such steam passesthereinto and thereby produce variation in the steam distributionprofile established at said steam distribution outlets.
 2. Steamdistributing apparatus according to claim 1 wherein said means forvariably regulating the passage of steam through a number of said portscomprises a plurality of valves, each valve being Mounted for regulatingthe passage of steam through one of said number of ports.
 3. Steamdistributing apparatus according to claim 2 wherein the passage of steamthrough all of said steam supply ports is variably regulated by saidplurality of valves.
 4. Steam distributing apparatus according to claim3 wherein said steam distribution outlets are substantially downwardlydirected, further comprising means forming a raised water barriersurrounding each of said steam distribution outlets internally ofchamber for resisting passage of condensation from the interior of saidchamber through said outlets.
 5. Steam distributing apparatus accordingto claim 1 wherein said steam distribution outlets are substantiallydownwardly directed, further comprising means forming a raised waterbarrier surrounding each of said steam distribution outlets internallyof said chamber for resisting passage of condensation from the interiorof said chamber through said outlets.
 6. Steam distributing apparatusaccording to claim 1 wherein said chamber is of polygonal cross sectionand said steam distribution outlets are grouped in a plane face thereofnearer to the junction of said plane face and one intersecting face thanto the junction of said plane face and another intersecting face wherebya condensate conduit is formed at said junction of said plane face andsaid other intersecting face when said plane face is angularly disposedto the horizontal so that said junction of said plane face and saidother face forms the lower extremity of said apparatus.
 7. Steamdistributing apparatus according to claim 6 further comprising meansforming a raised water barrier surrounding at least a portion of saidsteam distribution outlets internally of said second chamber forresisting the passage of condensate from the interior of said chamberthrough said outlets.
 8. Steam distributing apparatus according to claim1 wherein said means forming a plurality of steam supply ports comprisesa steam inlet manifold disposed internally of said chamber and connectedto a source of supply for conveying steam to diverse portions of saidchamber through said ports.
 9. Apparatus for distributing steamcomprising: a. an elongated steam inlet manifold forming a plurality ofports along the length thereof; b. means forming an elongated enclosedchamber surrounding the portion of said manifold along which said portsare distributed; c. means forming a multiplicity of steam distributionoutlets along the length of said chamber; and d. a plurality of valves,each valve being mounted for variably regulating the passage of steamfrom said manifold through an individual port into said chamber, tothereby vary the distribution of steam throughout said chamber andpermit the establishment of a variety of steam distribution profiles atsaid steam distribution outlets.
 10. Apparatus according to claim 9further comprising means outside of said enclosed chamber for adjustingeach of said plurality of valves individually.
 11. Apparatus accordingto claim 9 wherein said steam distribution outlets are substantiallydownwardly directed, further comprising means forming a raised waterbarrier surrounding each of said steam distribution outlets internallyof said chamber for resisting the passage of condensation through saidoutlets from the interior of said chamber to the exterior thereof. 12.Apparatus according to claim 9 wherein paid steam distribution outletsare arranged along one side of said enclosed chamber and said ports arearranged linearly along said manifold to face in a direction away fromsaid steam distribution outlets.
 13. Apparatus for distributing steamupon a travelling web comprising: a. means forming an elongated chamberadapted to be mounted above and extend substantially across said web; b.means forming a multiplicity of steam distribution outlets along thelength of a substantially downwardly directed portion of said chamber;c. an elongated steaM inlet manifold enclosed within said elongatedchamber and extending substantially lengthwise thereof, said manifoldforming a plurality of substantially upwardly directed ports fordistributing steam through said chamber; d. a plurality of valves, eachone of which regulates the amount of steam passing through one of saidports; e. means outside of said chamber for variably adjusting each ofsaid plurality of valves individually to thereby vary the distributionof steam throughout said chamber and permit the establishment of avariety of steam distribution profiles at said steam distributionoutlets; and f. means forming a raised water barrier surrounding each ofsaid steam distribution outlets internally of said chamber for resistingthe passage of condensate through said outlets from the interior of saidchamber to the exterior thereof.